AVS 50th International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuM

Paper SS1-TuM10
H@sub 2@ Production from Ethanol Over Au-Rh/CeO@sub 2@ Catalysts

Tuesday, November 4, 2003, 11:20 am, Room 327

Session: Catalysis II: Hydrocarbons at Metal Surfaces
Presenter: H. Idriss, The University of Auckland, New Zealand
Authors: H. Idriss, The University of Auckland, New Zealand
P.Y. Sheng, The University of Auckland, New Zealand
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The reactions of ethanol over oxides and metal-oxides surfaces are receiving increasing attention because of the potentially efficient production of hydrogen by oxidation and steam reforming.@footnote 1,2@ Ethanol (now viewed as a bio-fuel with potential for making hydrogen) has received considerable attention in the past because it is a simple probe molecule in studying surface reactions on metals@footnote 3@and oxides.@footnote 4@ We have previously investigated the decomposition of ethanol on M/CeO@sub 2@surfaces (M = Rh, Pt, Pd and Au).@footnote 1,5@ In this work we show that the addition of Au to Rh, for the reaction of ethanol, enhances both the production of H@sub 2@ and the total oxidation to CO@sub 2@. The reaction of ethanol was conducted by TPD, IR and in steady state catalytic conditions, while catalysts were investigated by XRD and XPS. Among the key results of this work are the following. 1. Addition of Au resulted in the total suppression of adsorbed CO when compared to Rh/CeO@sub 2@ catalyst (IR), at low temperatures. 2. The presence of Rh enhanced the production of H@sub 2@ and the total decomposition of ethanol when compared to Au/CeO@sub 2@ catalyst (steady state reactions). The CO@sub 2@ to CO ratios were found equal to 25 for Au/CeO@sub 2@, 5.6 for Rh-Au/CeO@sub 2@, and 1.8 for Rh/CeO@sub 2@, catalysts (TPD). The reaction pathway for ethanol on the bimetallic system will be discussed and compared to that on the mono-metallic catalysts. @FootnoteText@ @footnote 1@ Sheng, P.-Y., Yee, A., Bowmaker, G. A., Idriss, H. J. Catal. 2002, 208, 393; and references therein. @footnote 2@ Cavallaro, S. Freni, S. Int. J. Hydrogen Energy, 1996, 21, 465.@footnote 3@ Gates, S.M., Russell, J.N., Yates, J.T., Surf. Sci., 1986, 171, 111.@footnote 4@ Idriss, H., Seebauer, E.G., J. Mol. Catal. A, 2000, 152, 201.@footnote 5@ Diagne, C., Idriss, H., Kiennemann, A., Catal. Commun. 2002, 3, 565.